But are numbers important? And, is there a downside to having too many apps on offer?

There's no doubt that for any platform to be successful today it needs to offer its users a good selection of apps. The platform comes first, while the 'apps later' approach doesn't work. And in order to be able to do this, that platform needs a good base of developers to imagine and then build these apps.

We're also at the stage where people now demand certain apps to access specific services while on the move. Facebook and Twitter are two of the best examples. Not having an app for that, especially if it's available for other devices, might not kill a platform, but it can certainly be irritating to users. For example, Windows Phone doesn't offer apps for either Instagram or Pandora, while iOS and Android both do.

So, you need a critical mass of apps, and you need a set of core apps that people expect to be present. But beyond that, do the number of apps in a particular app store matter?

I don't think so. In fact, I feel that once your app count is in to big numbers, numbers become nothing more than a tool for marketing to wield, rather than being something that benefits the user.

Take Apple's 600,000 apps. That's a lot of apps, and it's impossible for someone to look at them all. If you looked at an app a second, it would take you almost seven days to look at them all - but I don't recommend you try it.

Having the ability to search gives the impression of making my life easier, but I have to admit that unless I happen to know the name of the app I'm looking for, I don't hold out much hope of finding the app. Finding the Facebook app or Instagram app or Angry Birds app is easy, but if I'm looking for something off the beaten track, things aren't as simple.

Just browsing around the app store is even worse. Here's a sobering thought for any developers reading this. Unless your app is in the top 25 list for a particular category, or I come across mention of it online or by word of mouth, chances are probably higher of me winning this week's lottery than there are of me finding your app.

And to be brutally honest, those top 25 lists are fast becoming useless. They're mostly populated by apps that I already have -- like Angry Birds, Facebook, Skype, and so on -- or apps that I never download, like Draw Something.

Will I trawl endlessly through app listings in search of something new and exciting? No.

The truth is Apple's App Store is already too big for me. Unless I know the app I'm looking for, or it is popular enough to float to the top in the listings, it may as well not exist. Apple's App Store may have 600,000 apps -- and bear in mind that some of those are going to be non-English apps that don't apply to me -- but as far as I'm concerned it consists of a few hundred apps that I'm likely to be exposed to, and nothing more.

Google's Android Market is the same. In fact, despite having fewer apps it feels messier, like walking into an old junk shop with everything piled on top of one another. "Curation" is a word that Google should look up on Google. The 'staff picks' do offer some variety, but not much.

Bottom line: It feels like Apple and Google have allowed their respective app distribution outlets to grow out of control. When you're hovering around the half a million app mark, it's hard to see what you can do to make it easier for people to find apps.

Better search would help, but not much. User ratings are useless because people's feedback always seems to be all over the place, and most often than not has little to do with the app itself and more to do with the price of the app.

This gives Microsoft an advantage. With only 70,000 apps, its app store is currently at a manageable level. It's early enough for the company to put some thought into how it plans to handle future growth before things get out of control.